Housed spark-over gap



L. PUMMER' HOUSED SPARK-OVER GAP Filed April 11, 1952 Ju1ie16, 1953 2,642,549

v INVENTOR. Leo Pummer BYZZ H: I a

fllloz'nw Patented June 16, 1 953 tionof Delawarc" Leo Pumm'er, Chicago, Ill.,; assign f'to Electric Company;'Milwaukee W ntwan Alir ll a iese l 1. This invention relates te improvements in; a housed spark-over gap.

It has been customary to providelightning ar 7 resters of the expulsion or Valve" type with' a" spark-over gap locatedon the-line side" of the arrester for the purpose of isolating the'arres'ter' from the line under normal operating conditions in the circuit protected thereby. I Frequently, these gaps have been exposed, especially whenused with expulsion-arresters, so that they might be bridged bysome-object, such'as- Thus, the removal of one source of troublemerely introduced another-sourceoi -trouble.-

.It is an object of thisinvention-to-provide a housing. for a gap in which metallic vapors-generated by an are are expelledfrom the housing and prevented from forming leakage paths on the walls of the housing between the electrodes therein.

Another more specific object is to provide a housing having an arcing chamber in which the gap is disposed more nearly approximate to the expulsion end of the chamber and the other end of the chamber is closed to provide an air pocket across which one of the electrodes extends, the air pocket being proportionally dimensioned to provide an air cushion that aids in the expulsion action and prevents metallic vapors from collecting on the walls of the chamber within the area of the pocket.

Other specific novel features will be disclosed as the description progresses.

Fig. 1 is a view in elevation, partly in section, illustrating a combined gap device and arrester.

Fig. 2 is a sectional view of the gap device taken on the vertical axis thereof.

Fig. 3 is a plan view of the gap as viewed from above Fig. 2.

Fig. 4. is a transverse section taken on the line -4 in Fig. 2. l

Details of the construction of the arrester A shown in Fig, 1 are not developed in the drawings, since they are well-known in the art. It is suflicient to note that it isof the expulsion type and is provided with a terminal rod I that extends outwardly of the top of they insulator housing 2 which usually is composed of porcelain. As indicated in Fig. 2 the protruding end 3 of the rod is threaded.

is I preferablyporcelai posed ofother'sui e insulating materiall' In the drawings, "the 1 housing, 4' is represented'fas cylindrical to provide an enlarged-air andi arci'ng ber" dterminatingjat the lowe'r'endin'anenthe "housing? 4";

Two'aperturesj IOand; l I; disposed at substane it tially relativet'o eachiotner, xtend through" the knob portior'i' e" radially of the restrictedi'bo're; 8; The aperture H). as indicated, in Fig. 2"ji slprefiera-bly slanted'downw'ardly and outwardly of'th'ebore-8 The-wallpfthebore 8 isfl providedlwith. two indents l2 and I3 diametrically"dpposit'theapertures Ill and II respectively.

Socketedi-nthebore't is'a cylindrical terminal.

block I I45 havihg an axially-extending openin 15,

- a; transverse aperture" l 6 normal to the opening. [5; and a threadediaperture ll registering with the aperture lfl in the-"knob portion9'. A clamping screw lfl is threadedinto the aperture IT and extends to the aperture [6 'for engagement with a.

I The conductor aperture- 1 6- is axially in' register" with the opening H in the knob 9 to facilitate insertionv of the conductor.

viously, the apertures 16 and I! in the block I4 and apertures I0 and II in the insulator knob 9 W11]. of necessity be closed to the entrance of the" material 20 while the block is being secured inv position.

24 on the mounting cap 25.

The mounting cap 25 comprises a metal plate with a series of openings 26 arranged circumferentially about the head 24 and is anchored againstthe annular shoulder 1 in the housing 4 by meansof any suitable material 21. As indicated in Fig.. 2, the head 24 includes a threaded recess 28 which engages the threaded end 3 on the rod I of the arrester. A resilient washer 29 is clamped device embodies? anousinga' which; or glass"; but may be com{ :d hallo'w borefeto form an annular seat T an terminating; at the upper. end; in restricted cylindrical bore; 8 within the knob portion- 97 ofl its lower end for expulsion of gases when the I air in the chamber is expanded in response to heat generatedby an arc across the gap. It will also be noted that the gap area between the electrodes is located in the region of the cap which includes the expulsion opening and in comparison is relatively remote from the closed end of the housing. As a result, any metal vapor generated by an arc betweenthei electrodes will be projected into the region adjacent the cap and that the air above that region will be exair containing the vaporized metal out of the housing through the openings 26. Any condensation of the vaporized metal that may collect on the walls of the housing will be confined to the surface immediately adjacent the arcing area and virtually none will reach the walls of the housing above that area. a

Since metallic vapor will be prevented from deposition on most of the wall :of the chamber,

it will be obvious that arcing between the electrodes will not produce a condition within the chamber which will establish leakage paths over the surf-ace of the walls of the chamber between the terminal block l4 and the cap 25.

The arrangement of the elements is a novel contribution in that it overcomes two serious problems, namely conceals the gap electrodes and prevents formation of leakage paths between the gap electrodes; a

Iclaim: v

i 1. In a spark-over gap device, the combination with a cup-like housing composed of insulating material and enclosing an elongated arcing chamberopen at one end and closed at the other end, of an apertured electrode plate secured in said open end, a terminal block secured in the closed end' and including conductor receiving and clamping means accessible from the exterior of said housing, and an elongated electrode expanded by the heat of the are and will-force the I 4 tending from said block adjacent the closed end of said housing to a point adjacent said plate and the apertures therein, the chamber in said housing being proportioned so that a major portion thereof is disposed about the length of said electrode and a minor portion surrounds the gap between'saidelectrode and plate.

2. In aspark-over gapidevice, the combination with an insulating housing open at one end and closed at the other, of a pair of electrodes in said housing forming a spark-over gap adjacent the open end thereof, one of said electrodes extending to the closed end fsaid housing and including connector, means; accessible exteriorly at said closed end, the major portion of the chamber in.

said housing surrounding said one of said electrodes being'dispo-sed between said gap and said closed end and the minor portion of said chamsaid open end, a restricted bore at the other end her surrounding said gap adjacent said open end.

I 3, In a sparkover gap device, the'combination with an insulating housingcomprising a cup-like member having an elongated chamber open at one end, an annular shoulder interiorly adjacent of said chamber having a pair of radial openings at substantially relative to each other and extending to the exteriorof the housing, of an apertured mounting cap mounted on said annular shoulder and secured thereto, said mounting cap having interiorly of said chamber an arcing head and-exteriorly a threaded recess, a terminal block in said restricted boresecured therein in sealed relation thereto and having a conductor receiving aperture registering with one of said radial openings and a clamping bolt registering with the other radial aperture and extending to said conductor receiving aperture, said block having a recess interiorly of said housing directly above said arcing head, and an elongated electrode having one end in push fit engagement with recess and an arcing head at its other end adjacent said arcing head.

. LEO PUMMER.

' No references cited. 

